1. Replace  ext_tar_cor.f in espace_lib subdirectory with
   new version.

2. Edit parameter.h in espace_lib subdirectory and add the
   lines


c    for correcting delta and theta_tg for x-target dependenc
      real  DEL_XTG_COR,THT_XTG_COR
      parameter(DEL_XTG_COR=5.18,THT_XTG_COR=.61)


3. A short writeup on how the coefficients were calculated
   see xtarget_corrections.ps